I am not obviously a professional but shall be going along with my D800 plus the wife and our baby. I need to travel light and will take just one lens. What do I have to choose from... ? Nikon 50mm 1.4, 24-120f4, 105 VR Micro 2.8 and probably 18-35G. I favour the 50mm as its light sharp and will be good in low light however I was wondering what experienced wedding photographers would choose?

A fast fixed 85mm. You don't have one, I'd take the 105 and get some decent portraiture and forget the rest, and have fun. Portraiture IS weddings...

At my cousin's wedding, the pros were using 70-200's mainly. My wife and I brought a 35/1.4 and the 105VR. A photo with each (note the ISOs, this was a dimly lit event):